Remove BrowserThread-specific implementation of MessageLoopProxy.

content/browser/browser_thread_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/browser_thread_impl.h"
 
 #include <string>
 
 #include "base/atomicops.h"
 #include "base/bind.h"
@@ skipping 157 matching lines @@
       message_loop->PostNonNestableDelayedTask(from_here, task, delay);
     }
   }
 
   if (!guaranteed_to_outlive_target_thread)
     globals.lock.Release();
 
   return !!message_loop;
 }
 
-// An implementation of MessageLoopProxy to be used in conjunction
-// with BrowserThread.
-class BrowserThreadMessageLoopProxy : public base::MessageLoopProxy {
- public:
-  explicit BrowserThreadMessageLoopProxy(BrowserThread::ID identifier)
-      : id_(identifier) {
-  }
-
-  // MessageLoopProxy implementation.
-  virtual bool PostDelayedTask(
-      const tracked_objects::Location& from_here,
-      const base::Closure& task, int64 delay_ms) OVERRIDE {
-    return BrowserThread::PostDelayedTask(id_, from_here, task, delay_ms);
-  }
-  virtual bool PostDelayedTask(
-      const tracked_objects::Location& from_here,
-      const base::Closure& task, base::TimeDelta delay) OVERRIDE {
-    return BrowserThread::PostDelayedTask(id_, from_here, task, delay);
-  }
-
-  virtual bool PostNonNestableDelayedTask(
-      const tracked_objects::Location& from_here,
-      const base::Closure& task,
-      int64 delay_ms) OVERRIDE {
-    return BrowserThread::PostNonNestableDelayedTask(id_, from_here, task,
-                                                     delay_ms);
-  }
-  virtual bool PostNonNestableDelayedTask(
-      const tracked_objects::Location& from_here,
-      const base::Closure& task,
-      base::TimeDelta delay) OVERRIDE {
-    return BrowserThread::PostNonNestableDelayedTask(id_, from_here, task,
-                                                     delay);
-  }
-
-  virtual bool RunsTasksOnCurrentThread() const OVERRIDE {
-    return BrowserThread::CurrentlyOn(id_);
-  }
-
- protected:
-  virtual ~BrowserThreadMessageLoopProxy() {}
-
- private:
-  BrowserThread::ID id_;
-  DISALLOW_COPY_AND_ASSIGN(BrowserThreadMessageLoopProxy);
-};
-
 // static
 bool BrowserThread::PostBlockingPoolTask(
     const tracked_objects::Location& from_here,
     const base::Closure& task) {
   return g_globals.Get().blocking_pool->PostWorkerTask(from_here, task);
 }
 
 bool BrowserThread::PostBlockingPoolTaskAndReply(
     const tracked_objects::Location& from_here,
     const base::Closure& task,
@@ skipping 147 matching lines @@
       return true;
     }
   }
 
   return false;
 }
 
 // static
 scoped_refptr<base::MessageLoopProxy>
 BrowserThread::GetMessageLoopProxyForThread(ID identifier) {
-  scoped_refptr<base::MessageLoopProxy> proxy(
-      new BrowserThreadMessageLoopProxy(identifier));
-  return proxy;
+  if (g_globals == NULL)
+    return NULL;
+
+  BrowserThread::ID current_thread;
+  bool guaranteed_to_outlive_target_thread =
+      GetCurrentThreadIdentifier(&current_thread) &&
+      current_thread <= identifier;
+
+  BrowserThreadGlobals& globals = g_globals.Get();
+  if (!guaranteed_to_outlive_target_thread)
+    globals.lock.Acquire();
+
+  base::Thread* thread = globals.threads[identifier];
+  if (!thread) {
+    if (!guaranteed_to_outlive_target_thread)
+      globals.lock.Release();
+    return NULL;
+  }
+  scoped_refptr<base::MessageLoopProxy> loop = thread->message_loop_proxy();
+
+  if (!guaranteed_to_outlive_target_thread)
+    globals.lock.Release();
+
+  return loop;
 }
 
 // static
 MessageLoop* BrowserThread::UnsafeGetMessageLoopForThread(ID identifier) {
   if (g_globals == NULL)
     return NULL;
 
   BrowserThreadGlobals& globals = g_globals.Get();
   base::AutoLock lock(globals.lock);
   base::Thread* thread = globals.threads[identifier];
@@ skipping 10 matching lines @@
   AtomicWord* storage = reinterpret_cast<AtomicWord*>(
       &globals.thread_delegates[identifier]);
   AtomicWord old_pointer = base::subtle::NoBarrier_AtomicExchange(
       storage, reinterpret_cast<AtomicWord>(delegate));
 
   // This catches registration when previously registered.
   DCHECK(!delegate || !old_pointer);
 }
 
 }  // namespace content